6mm vs 6.5mm, not quite beating a dead horse.

[IeatRocks]

I have a Tikka chambered in 308 and the barrel is starting to finally burn out. I am planning on doing a WTO switchlug and getting two barrels spun up. One will be the ol’ NATO potato and there is no way talking me out of that. The second barrel I am going back and forth on 6mm and 6.5mm. It’s mostly between 6gt and 260rem. Open to other suggestions but I’d like to mostly keep it between these two cartridges.

I understand the general advantages to each but looking at how significant those advantages. Both 308 and 6/6.5 barrels will be used in field style matches and local prs matches as well as just shooting for fun. Ranges routinely run out to 1400.

6gt; lighter recoil and the benefit of using Varget with both itself and 308. That is very convenient to only need one powder for both barrels.

260; slightly better wind although very slight from what I see comparing data. The 6.5 high BC bullets do their thing but the higher speeds of 6mm seem to help close that gap. Better splash/strike for making corrections.

So the question for those who have experience with both; Is the recoil reduction that great between the two in a 17ish-19ish lb gun with a suppressor/brake hybrid? And, is the difference in splash enough to make a big enough difference?

I’m sure I’d be fine and adjust to either cartridge but since I’m starting fresh (barrel, bullets, brass, dies) I might as well go with the better option, if any.

 

[DeathBeforeDismount]

6.5 gives you option of cheapish factory ammo that shoots well. .260 is dead and you can run into OAl issues with magazines with the heavies. If you are going to shoot alot of 1k-1.4k then the creed will be much better for spotting and the high bc bullets will stay supersonic longer.

H4350 is a better powder for 6gt and 6.5cm for a couple reasons. Varget you have to deal with carbon rings.

Barrel life is a thing. Run a hot 6 creed and you can torch the barrel at 1k. Run a slow BRA you can probably get 3-4k on the barrel. Same deal with creed. If you chase velocity you are going to burn it out faster.

I pull my 6gt barrels (run 2930 with 109) at 2k and my 6.5cm barrels at 3k ( running 2775 with 143s).

I run both. The recoil difference is not that much and each has its pros/cons for shooting steel.

 

[IeatRocks]

6.5 gives you option of cheapish factory ammo that shoots well. .260 is dead and you can run into OAl issues with magazines with the heavies. If you are going to shoot alot of 1k-1.4k then the creed will be much better for spotting and the high bc bullets will stay supersonic longer.

H4350 is a better powder for 6gt and 6.5cm for a couple reasons. Varget you have to deal with carbon rings.

Barrel life is a thing. Run a hot 6 creed and you can torch the barrel at 1k. Run a slow BRA you can probably get 3-4k on the barrel. Same deal with creed. If you chase velocity you are going to burn it out faster.

I pull my 6gt barrels (run 2930 with 109) at 2k and my 6.5cm barrels at 3k ( running 2775 with 143s).

I run both. The recoil difference is not that much and each has its pros/cons for shooting steel.

6.5 gives you option of cheapish factory ammo that shoots well. .260 is dead and you can run into OAl issues with magazines with the heavies. If you are going to shoot alot of 1k-1.4k then the creed will be much better for spotting and the high bc bullets will stay supersonic longer.

H4350 is a better powder for 6gt and 6.5cm for a couple reasons. Varget you have to deal with carbon rings.

Barrel life is a thing. Run a hot 6 creed and you can torch the barrel at 1k. Run a slow BRA you can probably get 3-4k on the barrel. Same deal with creed. If you chase velocity you are going to burn it out faster.

I pull my 6gt barrels (run 2930 with 109) at 2k and my 6.5cm barrels at 3k ( running 2775 with 143s).

I run both. The recoil difference is not that much and each has its pros/cons for shooting steel.

I looked into 260 since I reload. I figured it gave me a little more flexibility and case capacity, especially when running heavies to avoid running into compressed loads. The ctr mags for tikka are pretty long, I haven’t had issues loading 308 pretty long. Of the top of my head I think I can load to 2.995 with no issue in the mag. Throat/chamber could be an issue though.

6gt was similar vs the 6br. Larger case capacity and I’ve read they feed a little better but haven’t seen any issues with feeding at matches from other shooters.

With my atmospherics running 145s-147s at 2650fps I was actually going trans 25y before 110-115s going 2800fps. This was mocked up in AB quantum using velocity data I found from other shooters. Velocities seem to be a bit more mild but just trying to keep expectations real.

I haven’t bought factory ammo in years so it’s less of a concern. Components seem to be equally easy to find.

Not arguing at all, just explaining how I came up with those choices.

Thanks for the insight, it looks like it’s a point for 6.5 with splash.

 

[DeathBeforeDismount]

BR/Dasher mags have solved the feeding issue. If starting fresh a dasher or BRA would be my first choice. They just are inherently more accurate and easier to tune a load for.

if you are shooting far with the 6.5, run the 156 or 153 bergers with a 7.5 twist barrel. The 144 is also a really good bullet. Ultimately you will need to balance BC and velocity.

My factory norma 143 golden target is 2775. I could load it much hotter but for $1/round its not worth my time.

 

[IeatRocks]

BR/Dasher mags have solved the feeding issue. If starting fresh a dasher or BRA would be my first choice. They just are inherently more accurate and easier to tune a load for.

if you are shooting far with the 6.5, run the 156 or 153 bergers with a 7.5 twist barrel. The 144 is also a really good bullet. Ultimately you will need to balance BC and velocity.

My factory norma 143 golden target is 2775. I could load it much hotter but for $1/round its not worth my time.

Without changing chassis/stock I’m married to the CTR mags. I’m not sure if there’s a fix for the CTR mag or it’s even an issue though.

What length barrel are you running with your 6.5?

 

[DeathBeforeDismount]

26". Tikka barrels are notoriously slow. Don't be surprised to see a 100 fps increase just changing the barrel and keeping the length the same.

 

[dgheriani]

Honestly, I'd just skip the .260, it is essentially a dead cartridge, never mind the potential issues with OAL if running heavies.

Between 6.5 Creed and 6 GT (or Creed, they really aren't all that different) I honestly just think it's a question of what is more important for you, slightly better performance with lessened recoil or barrel life. I've run both 6 Creed (26" barrel, 110s going 2900) and 6.5 Creed (26" barrel, 140s going 2750-2800) for many years and many barrels (and still run both) and IMO the 6 Creed is pretty much the perfect field cartridge. It has better downrange performance, apples to apples, than the 6.5, is flatter (which helps with range uncertainty in UKD matches) and has less recoil so easier to spot trace but at about 2/3 the barrel life of the 6.5. I pull 6mm barrels at 2000 rds and 6.5s at 3000. If I can, I'll run a 6 Creed barrel for a UKD field match but some have a PF requirement (NRL Hunter) and some require mil calibers. All that is not to say that the 6.5 is no good, in fact it's great, leagues better than your Nato-potato, haha, it's just ever so slightly out-classed by the 6 Creed for field UKD matches. How much that matters to you is the crux of the issue.

 

[IeatRocks]

Honestly, I'd just skip the .260, it is essentially a dead cartridge, never mind the potential issues with OAL if running heavies.

Between 6.5 Creed and 6 GT (or Creed, they really aren't all that different) I honestly just think it's a question of what is more important for you, slightly better performance with lessened recoil or barrel life. I've run both 6 Creed (26" barrel, 110s going 2900) and 6.5 Creed (26" barrel, 140s going 2750-2800) for many years and many barrels (and still run both) and IMO the 6 Creed is pretty much the perfect field cartridge. It has better downrange performance, apples to apples, than the 6.5, is flatter (which helps with range uncertainty in UKD matches) and has less recoil so easier to spot trace but at about 2/3 the barrel life of the 6.5. I pull 6mm barrels at 2000 rds and 6.5s at 3000. If I can, I'll run a 6 Creed barrel for a UKD field match but some have a PF requirement (NRL Hunter) and some require mil calibers. All that is not to say that the 6.5 is no good, in fact it's great, leagues better than your Nato-potato, haha, it's just ever so slightly out-classed by the 6 Creed for field UKD matches. How much that matters to you is the crux of the issue.

Are tou pulling at 2k from signs of them letting go?

 

[BobinNC]

From the "For what it's Worth" department. I have both a .308 Win and a 6.5 Creedmoor. It's a nice pairing. Great accurate factory supported rounds (If your feeling flush), and easy to reload for with a dizzying array of cases to choose from, LR and SRP primer setups, and more good bullets for both hunting and targets, that it's sometimes hard to choose.

Toss in a 5.56 either in bolt action or AR form and the world is your oyster.

 

[CK1.0]

I think if one is still in that intermediate stage where they’re still working on spotting all their splash/impacts, or are new to that, 6mm and it’s lower recoil makes learning that and mastering it a fair bit easier.

But, if one has a good handle on seeing their shots (to the point where they see just about every single one out of a 6mm), then at that point moving to a larger 6.5mm that provides more visual feedback downrange can be worth the squeeze.

It can take a good amount of rounds downrange for one to get good at seeing every shot and to develop the recoil-management that goes with getting there, so I think for most a 6mm is probably easier to pick it up.

The advantage of having more visual feedback downrange is real though… so if one can really manage their recoil, bigger may be better.

Everything is relative though, and there’s some overlap where there can be different strokes for different folks… like I’d rather shoot a low-recoil heavier-for-caliber 115gn 6mm then mess with the headaches that come with a 25cal, and if one isn’t going to go whole hog on a new wave 6.5mm with the requisite 153.5/156 heavies and faster 7.5T stick to balance out the recoil trade-off, then the real difference becomes arguable.

 

[IeatRocks]

I think if one is still in that intermediate stage where they’re still working on spotting all their splash/impacts, or are new to that, 6mm and it’s lower recoil makes learning that and mastering it a fair bit easier.

But, if one has a good handle on seeing their shots (to the point where they see just about every single one out of a 6mm), then at that point moving to a larger 6.5mm that provides more visual feedback downrange can be worth the squeeze.

It can take a good amount of rounds downrange for one to get good at seeing every shot and to develop the recoil-management that goes with getting there, so I think for most a 6mm is probably easier to pick it up.

The advantage of having more visual feedback downrange is real though… so if one can really manage their recoil, bigger may be better.

Everything is relative though, and there’s some overlap where there can be different strokes for different folks… like I’d rather shoot a low-recoil heavier-for-caliber 115gn 6mm then mess with the headaches that come with a 25cal, and if one isn’t going to go whole hog on a new wave 6.5mm with the requisite 153.5/156 heavies and faster 7.5T stick to balance out the recoil trade-off, then the real difference becomes arguable.

Great insight! I rarely have issues with spotting rounds with my 308. With 178s only moving at 2595 it’s easy to get back on target before the round gets there if I don’t manage my recoil well lol.

At matches, I’ve never had a tough time spotting other shooters rounds but I’m not always sure what they are shooting. I have to imagine I’m watching a variety of 6mms, 6.5mms, and the ol potato. My only good side by side comparison is when shooting my 5.56 out to the further ranges. There is an incredible difference compared to the 308, especially in the sage brush I’m often shooting into.

 

[codym]

I don’t have a 6.5 creed but have several 25 creeds 6 creeds and 6 dashers. I also have a 20’ 260AI. The 260 has been very impressive to me. I run 140 hybrids at 2830 and the 156’s at 2720 with RL 16, pretty darn impressive to me out of a 20’ barrel. Recoil out of my 25 creed (both 12 pound NRL light rigs) is almost indistinguishable to me 140 2830 vs 135 (2860) and my real world wind holds are generally the same obviously slightly more drop with the 260. My favorite creed is still the 6. Super easy to tune significantly less recoil that the 25 or 260 and the ballistics with the 109 hybrid at 3030 line up very closely to my 25. The 6 creed has been simple to tune where the 25’s have been much finickier. The easiest of all with the least amount of recoil and best barrel life is the dasher just simple 105/109 hybrids, varget and cci450’s 31-32.2 grains will have you shooting tiny little groups. I doubt there’s a wrong answer and these are just my observations/opinions. Honestly pick one and if you really get into it you most likely will want to try something different in a barrel or two… that’s part of the fun

 

[XP1K]

The nato potatoe. Yeah, I'm gonna borrow that.

The potatoe and the gay tiger sound like a good pair.

 

[IeatRocks]

I don’t have a 6.5 creed but have several 25 creeds 6 creeds and 6 dashers. I also have a 20’ 260AI. The 260 has been very impressive to me. I run 140 hybrids at 2830 and the 156’s at 2720 with RL 16, pretty darn impressive to me out of a 20’ barrel. Recoil out of my 25 creed (both 12 pound NRL light rigs) is almost indistinguishable to me 140 2830 vs 135 (2860) and my real world wind holds are generally the same obviously slightly more drop with the 260. My favorite creed is still the 6. Super easy to tune significantly less recoil that the 25 or 260 and the ballistics with the 109 hybrid at 3030 line up very closely to my 25. The 6 creed has been simple to tune where the 25’s have been much finickier. The easiest of all with the least amount of recoil and best barrel life is the dasher just simple 105/109 hybrids, varget and cci450’s 31-32.2 grains with have you shooting tiny little groups. I doubt there’s a wrong answer and these are just my observations/opinions. Honestly pick one and if you really get into it you most likely will want to try something different in a barrel or two… that’s part of the fun

Sure is! I’m constantly finding a new wildcat that enters the “maybe I should go that route instead” lol.

How is splash with dasher compared to the 25/260ai? I know from a physics standpoint it’s there but does it make much difference to the shooters eye?

The recoil vs splash between the 6mms and 6.5mms seems to be a lot more about the Indian than the bow. However, it’s always worth stacking the cards in my favor.

I’m starting to put 6 creedmoor into the list now with the recommendations. My only concern is long strings of fire. Some of these field matches I’ve shot there are no round counts, just time and penalties. I hate brining barrel life into the equation but it does weigh into the decision. I’ve read and heard everything from 800rds to 2500rds but the average seems to be around 1500.

For the 6mm creedmoor shooters, do you guys have to continually tune to account for throat erosion or is it more tuning to milk the last few hundred rds?

 

[IeatRocks]

The nato potatoe. Yeah, I'm gonna borrow that.

The potatoe and the gay tiger sound like a good pair.

Please do! Not my creation but I haven’t stopped calling it that since I first heard it.

 

[codym]

Honestly the Splash here in the southwest isn’t hard to read but you can definitely can read the plate better impact wise with the 25/260. At bigger plates at farther distances sometimes impact verification can be a little harder. My experience with the 6 creed is not chasing the lands. I run it until velocity drops off or accuracy drops off and a deep clean can’t get it back.

 

[CK1.0]

Sure is! I’m constantly finding a new wildcat that enters the “maybe I should go that route instead” lol.

How is splash with dasher compared to the 25/260ai? I know from a physics standpoint it’s there but does it make much difference to the shooters eye?

The recoil vs splash between the 6mms and 6.5mms seems to be a lot more about the Indian than the bow. However, it’s always worth stacking the cards in my favor.

I’m starting to put 6 creedmoor into the list now with the recommendations. My only concern is long strings of fire. Some of these field matches I’ve shot there are no round counts, just time and penalties. I hate brining barrel life into the equation but it does weigh into the decision. I’ve read and heard everything from 800rds to 2500rds but the average seems to be around 1500.

For the 6mm creedmoor shooters, do you guys have to continually tune to account for throat erosion or is it more tuning to milk the last few hundred rds?

A 25/260/6.5 is going to have noticeably more splash than a Dasher... caveat: that's only if you have the recoil-managment to see it.

It really is a cost-benefit analysis of recoil versus splash... and for a lot of guys that's going to be 6mm, because it's plain easier to spot with less recoil in a gun of the same weight. Remember, the pros and other experienced shooters who've started migrating towards the larger calibers and heavier projectiles have been doing the "soft 6mm thing" for a long time, and mostly have that down.

Sometimes it's not just about the cartridge; the weight of the rig matters too. Like, I like the feel of my 22-23lb 6GT (and I know more than a few guys who are running 25+lb 6mm guns now so that might seem light to some). But if I were to jump to 6.5CM tomorrow, like it or not, I'd have to either get better, make my gun a little heavier, or likely a mix of both, to hopefully see my shots the same way I see them now. Physics is physics.

In many ways, the cartridge doesn't even really matter; just decide what recoil-impulse seems like would be right for where you're at (and/or how heavy a rig you're prepared to try hauling around).

I shot 6CM for a decent amount of time (smoked 5 barrels) before switching to 6GT, and honestly, if I knew then what I know now, there's a good chance that maybe I would have just stuck with 6CM...

But here's the thing: when talking about 6mm Creedmoor, are we talking about the old "legacy 6CM" from 10 years ago when it first came on scene and guys were pushing it to 3000+fps that keyboard warriors who don't shoot a whole lot talk about, or are we talking about "recent/modern 6CM" where guys who actually know better run it between 2800-2900(ish)fps..?

Because their aren't very many guys who actually shoot a lot who are running 6CMs at ~3000fps anymore (unless they just enjoy cooking barrels every ~1200rds for some reason). Going that fast (for really no good reason) tends to be viewed as plain dumb these days, as it's fairly widly accepted as fact that a faster gun that has more recoil and eats barrels < a slower gun with a milder recoil impulse that's easier to spot and lasts long enough to learn some shit before you need to order another barrel.

If a guy is looking to run a 6mm and hoping to get 2000+ to 2500+ rounds out of a barrel before it's toast, then they're running it between ~2750-2900fps, and when run in that range, a 6mm is a 6mm (for the most part) and they all act relativly the same. Yeah, some are more efficient and/or may offer lower recoil due to reduced capacity (BRs, Dasher), while some offer more powder and projectile flexability (6x47L, 6GT, 6CM), and maybe some might seem to be a little easier to tune or find a good load for than others, but at the end of the day they all do the same things. Any of them willl work and be WAY easier to spot than the 'ol "NATO Potato" lol.

IMHO, I'd say look at a smaller 6mm, because capacity/speed is overrated, but heavier high-BC bullets aren't, so consider that too.

(FWIW, my favorite 6CM load is a recipe that just about any fudd would tell you is totally wrong and breaks all the rules: a 6 Creed going "slow", using a fast powder, with a heavy bullet. 36 grains of SWPR/Varget under a 115DTAC going ~2800fps yields decent SDs and groups where they all touch and hammers out far, with ~2500rds of barrel life. There's so much room in the cases, they sound like salt and pepper shakers lol.)

 

[dgheriani]

Are tou pulling at 2k from signs of them letting go?

Mostly as a precaution. I've probably been through 6 or so 6 Creed barrels at this point and I keep running them for practice once I've pulled them from match use (at 2k rounds) and they still shoot fine to 2500 but I'd rather not run the risk of getting one that goes prematurely mid-match. I also don't run them hard. When I first started in 6 Creed (2018?) I was pushing 110 SMKs at 3150. I learned real quick that it was much easier to watch what was happening downrange with the same bullet going 2900 and most of the performance that you lost was in elevation so not really a huge deal being that 2900 is still plenty flat for UKD. 42.0gr of H4831sc with a 110 has shot bugholes in every barrel I've tried it in and gives me about 2900-2950 in a 26" barrel.

 

[CK1.0]

I ran 2900-2950fps for my first 3 barrels of 6CM and it went pretty much the same way, ~2000rds on them and I wouldn’t take them to a match. They’ll go longer for practice, but I wouldn’t bet on getting a consistent 200+ rounds out of them between cleanings at that point anymore.

I hopped back and fourth between the 6CM and 6GT for a while, shooting them at nearly the same speeds, first by running the GT hotter to hang with the CM, before then experimenting with slowing them down, finally ending up with running both ~2800-2850fps. Run slower, they seem to hang around longer and are more consistent between cleanings, I’d take one to a match with 2K on it without feeling the need to pull it.

 

[Vace9089]

Ive owned both and love both. 6mm has a fun factor that 6.5 doesn't have. It's less recoil and it's a laser beam in comparison when launching 110 class bullets near 3100 fps. Both are easy to load for but I feel 6.5 is less temperamental. 6.5 also definitely gives off better splash signatures than the 6mm so there's also that to consider when spotting misses. I have not hunted with the 6mm, but the 6.5 is definitely my current preference for whitetails.

 

[Rob01]

I looked into 260 since I reload. I figured it gave me a little more flexibility and case capacity, especially when running heavies to avoid running into compressed loads. The ctr mags for tikka are pretty long, I haven’t had issues loading 308 pretty long. Of the top of my head I think I can load to 2.995 with no issue in the mag. Throat/chamber could be an issue though.

6gt was similar vs the 6br. Larger case capacity and I’ve read they feed a little better but haven’t seen any issues with feeding at matches from other shooters.

With my atmospherics running 145s-147s at 2650fps I was actually going trans 25y before 110-115s going 2800fps. This was mocked up in AB quantum using velocity data I found from other shooters. Velocities seem to be a bit more mild but just trying to keep expectations real.

I haven’t bought factory ammo in years so it’s less of a concern. Components seem to be equally easy to find.

Not arguing at all, just explaining how I came up with those choices.

Thanks for the insight, it looks like it’s a point for 6.5 with splash.

Of course @Terry Cross liked a .260 shout out. lol

On a serious note, if you are set on a .260 then have at it. I run my 28” 6.5 Creed with 153 ATips at 2680fps with H4350 and you should be able to do similar. You can shoot the lighter bullets also if you wanted. I have used 140s for years, AMAX first and now ELD-Ms, and have shot them out to a mile. I’d suggest a 28” barrel if you go .260 to get a little more velocity without having to push it hard.

As mentioned the speed of the 6mm will help determining barrel life. I run my 6Creed with 110s at 2910fps so will get similar to any of the slower 6mm for barrel life. The 6Creed got the barrel burner rep back when it first came out and the matches were different and people were running them at 3150fps. Now everyone is running slow 6mms as you know the range so the speed isn’t needed and people want less recoil.

 

[ramslammer]

Just my 2 cents. 26 inch Brux 6gt 115 dtac 6.5 Staball at 2850 strikes a balance of caliber,bc,speed barrel life accuracy and recoil.